Errors running CutyCapt on Centos 5.7 without X Server

Question

Having everything installed and compiled successfully, I am getting this lovely output, anyone has an idea? (it's a centos 5.7 without x server, so I am emulating this using the infamous xvfb-run)

./xvfb-run ./CutyCapt
Locking assertion failure.  Backtrace:
#0 /usr/lib64/libxcb-xlib.so.0 [0x7f58396d690c]
#1 /usr/lib64/libxcb-xlib.so.0(xcb_xlib_unlock+0x24) [0x7f58396d6a14]
#2 /usr/lib64/libX11.so.6 [0x7f58399260f0]
#3 /usr/lib64/libXfixes.so.3(XFixesQueryVersion+0x4f) [0x37e8a03c9f]
#4 /usr/lib64/qt47/libQtGui.so.4 [0x7f583b7268ce]
#5 /usr/lib64/qt47/libQtGui.so.4(_ZN19QApplicationPrivate9constructEP9_XDisplaymm+0xde)         [0x7f583b6a741e]
#6 /usr/lib64/qt47/libQtGui.so.4(_ZN12QApplicationC1ERiPPcbi+0x78) [0x7f583b6a8088]
#7 ./CutyCapt(_ZN8QWebPage13triggerActionENS_9WebActionEb+0x1756) [0x4049be]
#8 /lib64/libc.so.6(__libc_start_main+0xf4) [0x312481d994]
#9 ./CutyCapt(_ZN7QObject5eventEP6QEvent+0x161) [0x4039e9]
CutyCapt: xcb_xlib.c:82: xcb_xlib_unlock: Assertion `c->xlib.lock' failed.
./xvfb-run: line 168:  2362 Aborted                 DISPLAY=:$SERVERNUM XAUTHORITY=$AUTHFILE     "$@" 2>&1

for comparison, this one runs OK:

./xvfb-run /usr/bin/xclock

Answer 1

I have fixed this by setting LIBXCB_ALLOW_SLOPPY_LOCK environment variable:

export LIBXCB_ALLOW_SLOPPY_LOCK=1

Answer 2

The problem is in libX11.

I got this problem after Cpanel upgraded libX11 to a later version (1.1.3). When I downgraded to version 1.0.3 then problem disappeared.